A frequency modulation (FM) receiver uses a radio data system (RDS) unit or a radio broadcast data system (RBDS) unit for processing specific data, for example station identification, song title, time, program identification, and name of artists, received from a broadcast station. The data is encoded and modulated before transmission. The data can also be referred to as digital information. The FM receiver receives a signal, and demodulates and decodes the signal using the RDS unit or the RBDS unit to obtain the data. Sensitivity of the RDS unit or the RBDS unit determines range and operating conditions in which the data can be decoded reliably and displayed to a user. To improve user experience it is desired to improve processing of the signal including the data and hence improve the sensitivity of the RDS unit or the RBDS unit.
Typically, the data is encoded using a shortened cyclic code and modulated using a differential binary phase shift keying (BPSK) modulation scheme. In one existing technique, the FM receiver uses a differential demodulation technique for demodulation and a burst error correction technique for error correction in demodulation and decoding. However, the burst error correction technique can only correct errors that occur in a burst (consecutive locations) with a burst length not exceeding five. For example, the burst error correction technique can correct bit errors occurring in consecutive locations in a bit length of 5. Hence, only a low percentage of 2-bit errors occurring in a block processed by the burst error correction technique can be corrected and thus the burst error correction technique is not optimal in presence of additive white Gaussian noise that is often present. The differential demodulation technique also results in low performance gain in decibels and low sensitivity performance.